Heartwarming Children's Story

I need a heartwarming short story for children. The story should be engaging and convey a moral lesson.

Requirements:
- The story should revolve around a small town boy, Arin, known for his mischievous behavior.
- A stray puppy changes his perspective.
- The narrative should be simple yet captivating, suitable for a young audience.
- The tone should be heartwarming, highlighting themes of kindness and change.

Ideal Skills:
- Experience in children's literature
- Strong storytelling abilities
- Ability to convey emotions and morals through writing

Please provide a sample of your work.